Display devices like waveguide based solutions and projection solutions can be implemented using bandwidth selective optical elements. A near-eye display (NED) device, such as a head mounted display (HMD) device, may be worn by a user for experiences such as an augmented reality (AR) experience and a virtual reality (VR) experience. A NED device includes an image generation unit, often called a light engine, for generating an image which is optically coupled into the near-eye display (NED) which may be implemented using waveguide technology which NED directs the image into the eye of the user so the user sees a projected image.
In practice, a NED waveguide module may include a stack of multiple waveguides, with each waveguide assigned to a wavelength range or wavelength band also referred to as a waveband. Multiple waveguides are useful as color spectral bandwidth in the visible spectrum can be fairly wide. The multiple waveguides support more color hues, creating more realistic imagery when viewed by a human eye. However, for diffractive waveguides, diffraction gratings which couple light in and out of the waveguide do not accommodate wide bandwidths well. More layers of waveguides can be added in a stack to each deal with different portions of color bandwidths, but that also adds more cost and weight and size to the NED, a device a human typically wears on his or her head.